This seminar is a part of the activities of Center for QIT of Spacetime and Matter and Center for Strings, Gravitation and Cosmology of IIT Madras
I will describe aspects of entanglement and extremal surfaces in certain AdS cosmologies and de Sitter space. In the first part, I will review certain families of AdS cosmologies with Big-Crunch singularities, including AdS Kasner, obtained as time-dependent deformations of AdS/CFT and their duals. I'll then describe spacetimes with cosmological singularities in 2-dimensional dilaton-gravity-matter theories, in part obtainable by dimensional reduction. I will then discuss aspects of classical and quantum extremal surfaces in these theories. In the second part, I will describe certain explorations of extremal surfaces in de Sitter space motivated by dS/CFT. I will discuss various aspects of future-past surfaces in de Sitter space, and entanglement in ghost theories, and finally close with some speculations.